Evolutionary Voicings, Part 1

At the heart of Barry Harris’s Theory of Evolution is the chromatic scale, shown on the top staff with enharmonic equivalents (i.e., different note names representing the same pitch, such as D sharp and E flat).Separate the solid and hollow noteheads, and you’ve got the two whole-tone scales (middle staff). Also derived from the chromatic scale are the three diminished 7th chords (bottom staff). Note that each includes two tritones: one from each whole-tone scale.

Each diminished 7th chord yields four dominant 7th chords. Just pick a note and lower it one-half step; this note then becomes the root of the dominant 7th chord. Shown below are the four dominant 7ths that relate to C#dim7 – Barry Harris would like you to keep the relationship between these four dominant 7ths in mind. Did the math already? That’s right, three diminished 7th chords means twelve dominant 7ths in all.

Dominant 7th chords generated by the same diminished 7th chord are functionally related. You can use them as substitutes for one another or choose one as the basic voicing and combine it with any of the others to make an extended dominant.

From the diminished 7th chord you can also create major 6th chords (left) and minor 6th chords (right). These chords sound the same as their corresponding minor 7th and minor 7 flat 5 chords, respectively. For functional reasons that we’ll cover in subsequent examples, think of them in their 6th forms.

Thinking of C as the tonic for both a major and a minor scale, here are major and minor 6th chords of that scale along with a diminished 7th chord. See examples 6 and 7.

Put the major 6th chord in Example 5 together with a diminished 7th chord, and you get what Barry likes to call the major 6 diminished scale.

Put the minor 6th chord of Example 5 together with a diminished 7th chord, and you get Barry’s minor 6 diminished scale.

An interesting and useful feature of the major 6 diminished scale is that it contains two dominant 7th chords: the V7 of the tonic and the V7 of the relative.

Playing a minor 6 diminished scale beginning a half-step higher than the root of a dominant 7th chord covers the root, 3rd, minor 7th, and all of the commonly used altered tones. You can even think of the minor 6 diminished scale as an altered scale when you use it this way.

Here are some starting points for seeing the relationships between 6th voicings and their functional equivalents: a) For major 7th chords, play the major 6th chord whose root is the fifth degree of the major scale. b) One approach to a dominant 7th voicing is to play the minor sixth chord on the fifth degree of the dominant. c) Another dominant 7th approach is to use the minor 6th chord whose root is one-half step up from the root of the dominant. d) Minor 7th chords are just inversions of major 6th chords, so this combination is natural. e) The same goes for minor 7 flat 5 and minor 6th chords. With the latter two examples, thinking in terms of 6th voicings opens up the possibility of moving voicings along a corresponding major or minor 6 diminished scale and then resolving to the next chord, rather than to simply hold a static voicing.

As we discussed in Examples 2 and 4, dominant 7ths derived from the same diminished 7th can be used as substitutions for each other. Here is B flat 7 resolving to E flat maj7, and voiced with three substitutions over a shell voicing in the left hand: a) an E7 resolving to a B flat 6 voicing over the E flat maj7, b) a G7 resolving to another inversion of the B flat 6, and c) a D flat 7 resolving to yet another B flat 6 inversion. Where are the chord symbols, you ask? We could include them as they appear with alerations in Example 4, but Barry wants you to focus on the basic structure of the voicings. As we’ll see momentarily, this makes them easier to move along a scale.

You can float those dominant substitute voicings up the diminished 7th arpeggio.

Let’s put Barry’s voicing ideas from Example 10 to work in a ii7-V7-IM7-VI7 progression.

Continuing in the manner of Example 14, we have the ii7-V7-I7-VI7 progression with the dominants voiced differently. Practice these voicings in different inversions.

As in Example 15, here is another voicing approach. Practice these voicings in different inversions, too.

A fun way to get familiar with moving voicings up and down the major and minor 6 diminished scales is to practice playing voicings in contrary motion. Using the C major 6 diminished scale, start with a unison, and then as you move up and down the scale stepwise, fill in the voicings between the outer voices. You’ll find that you’re always alternating between the major 6th chord and the diminished 7th chord, which is in effect a I to V motion.

Take the basic closed voicings and run them up and down the scale, which in this case is the C minor 6 diminished scale. The result is alternating minor 6th and diminished 7th chords. Experiment with dropping or octave-displacing certain notes to obtain open voicings, as shown on the bottom staff.

Who says you have to confine a voicing to either the 6th chord or the diminished 7th chord of the 6 diminished scale? You can borrow notes from one to use with the other if it creates a sound that intrigues you. Here, we’ve replaced the 6th of the tonic minor 6th chord with the major 7th. You’re likely to hear sounds you haven’t heard before as you take this voicing up the scale. Try the voicings on the lower staff as well.

This voicing resolves the “borrowed” note to a chord tone, for example, the major 7th (B) to the major 6th (A) over the first minor 6th chord.

Time to start putting things together. The first chord has two borrowed notes (the B’s), which resolve in contrary motion to chord tones. That upward resolution in the left hand can be a useful device for those who can’t reach the interval of a tenth. The progression repeats moving down stepwise.

The first chord in this progression is Am7 flat 5, over which you see voicings from the C minor 6 diminished scale. These resolve to the E flat m6/D7 on the fourth beat, and then on to the Dmaj6/Gmaj7. This serves to illustrate that you don’t have to wait until the dominant chord to start creating movement with your voicings.

Another twist to the borrowed tone idea: Since the diminished 7th chord represents four dominant 7th chords, why not “borrow” the root of one of those dominants for use in a diminished 7th voicing? When it creates a major 7th with the dropped note of the voicing, it can be most effective, as you see with the E in the second voicing, the D flat in the fourth, the B flat in the sixth, and the G in the eighth.

Why not borrow two dominant roots for the same diminished chord? As you can see on beat two, the first voicing has an E and a B flat, which are roots of two of the four dominant 7th chords related to the diminished chord of this scale. They resolve upwards to the full diminished 7th chord on the second half of the beat. As the pattern continues down the C major 6 diminished scale, note that nice, crunchy major 7th sound that happens before the borrowed tones resolve to the diminished 7th.

Here we precede each F6 with its neighbouring diminished 7th chord from the F major 6 diminished scale. This can be used over a Dm7 to create motion toward the resolution on a G7.

This example takes the same tack as Example 21 but adds a borrowed tone in the diminished 7th chords in the form of a root from one of the related dominant chords.

Apply example 25 to a ii-V-I in C, and this is one possible result.

Apply Example 26 to a ii-V-I in C, and you might come up with this.

This is another approach to resolving borrowed tones. In the first bar, the E and C sharp are borrowed from the diminished 7th chord of the F major 6 diminished scale; they resolve down to the Fm6. The progression continues in a similar manner until the last bar, where something interesting occurs: What seems at first glance to be a straight-ahead major 9th voicing actually contains three notes borrowed from the A flat major 6 diminished scale (G and B flat). Rather than being static, these notes are unstable in the context of a major 6 diminished scale and can resolve down to the chord tones of an A flat 6.